Coverage Gap Inventory — 2026-07-04

Produced by the enterprise readiness pass (PROD-105). Collected with coverlet.collector (now referenced by all 6 test projects) via dotnet test -c Release --framework net8.0 --collect:"XPlat Code Coverage", without local DB containers — SqlServer/MySql/Postgres integration tests were skipped (713 skips), which matters for interpreting the zeros below.

This is a handoff inventory: tests for these gaps are to be written by a follow-up work, not part of this pass.

Test suite status (all green)

4,369 passed / 0 failed / 714 skipped. Skips = DB-dialect integration tests (SqlServer/MySql/Postgres) that require containers; the full core suite was last verified against a SQL Server 2022 container on 2026-07-03 (3,587/3,589).

Per-assembly line coverage (SQLite-only run)

Genuinely untested (suites run fully locally; these are real gaps — write tests)

Priority order for the test-writing work:

1. Jaunty.Fluent.JoinedQuery4Builder<T1..T4> — 0/164 lines, and Jaunty.Fluent.JoinClause4Builder<T1..T4> — 0/43. The whole 4-entity join surface is untested (relates to PRD-007 3-way/4-way join parity).
2. Jaunty.Fluent.Internals.QueryBuilderBase — 0/72.
3. Jaunty.JauntyLoggingExtensions — 0/34 (public logging API, shipped in core).
4. Jaunty.TypeHandlers.TypeHandlerRegistry — 42% (15/36); Remove/replace paths untested.
5. Jaunty.FlatFiles.FileSources.ExcelFileSource (0/33), DeltaLakeFileSource (0/21), IcebergFileSource (0/24) — advertised file formats with zero tests (pure SQL-generation logic, no external deps needed).
6. Jaunty.FlatFiles.Core.FlatFileOptions — 38% (28/73).
7. Jaunty.Scaffolding.Providers.MySql.MySqlTypeMapper (0/53) and PostgreSql.PostgreSqlTypeMapper (0/63) — pure type-mapping logic, unit-testable without a database (SQLite/SqlServer mappers ARE tested; these two are not).
8. Jaunty.FlatFiles.DuckDB.Internals.Import.ImportDialectResolver — 30% (6/20).
9. Jaunty.Extensions.Reflection.MetadataCache<T> — 50% (77/155).
10. Jaunty.Jaunty (core static API surface) — 42% (419/1000): large #if-net472/ ns2.0 sections and provider-conditional paths dilute this; needs member-level triage after container-backed collection (see below).

0% only because containers were absent (verify with container run before writing tests)

• Jaunty.Extensions.Reflection.BulkCopy.{MySql,PostgreSql,SQLite,SqlServer}BulkCopyProvider and the 4 *DialectWithBulkCopy classes. Note: SQLiteBulkCopyProvider at 0/84 is suspicious even for a SQLite-capable run — likely genuinely untested; check first.
• Jaunty.FlatFiles.DuckDB.Internals.Import.{PostgreSql,SqlServer}ImportDialect.
• Jaunty.Scaffolding.Providers.{MySql,PostgreSql,SqlServer}SchemaReader.

Action for CI (PRD-015 extension): run coverage collection in the CI job that has the SQL Server container, and publish the cobertura artifact so the two categories above can be separated definitively.

Known failing/flaky (environmental, from prior reports)

• MySQL table-state isolation in Jaunty.Tests Release mode (47 failures when run against live MySQL; March 2026 audit finding, still open — test-fixture cleanup).
• 2 CS8600 warnings in TypeHandlerRoundTripTests.cs (lines 157, 229).

How to reproduce

dotnet test Jaunty.slnx -c Release --framework net8.0 \
  --collect:"XPlat Code Coverage" --results-directory ./coverage